Flipsky told us they changed the resistors on the 4.20 plus and that is uses two NTMFS5C628NL MOSFETs in parallel for each channel (so the resistors are 22 ohm); they told us they would send us a sample for testing, we will get back to you guys on its performance once they send us one for testing.
Since it uses two MOSFETs in parallel it should in theory be able to handle 40% more current.
Omg thanks a lot. I put a lot of hope to this 4.20 due to its form factor. But the cutouts are so irritating. Thanks for this finding. Now I can enjoy riding my board again!
Hmm… I have a feeling there’s a decimal place error. It’s likely that the engineers at Flipsky originally wanted 47 but then somehow 4.7 is passed along to manufacturing
Original VESC 4 schematic called for 4.7 ohm resistors, so I think they copied the schematic and didn’t realize the slew rate on new MOSFETs would cause such a problem.
Just want to reiterate
@nickw1881 has a valid point about dead-time insertion, please do some bench testing before use and let us know if there are any heat issues.
Just installed the Dual Flipsky 4.20.
Metr.pro record from a nighttime golf course ride yesterday.
Running 12s2p, 65 motor amps 20 battery amps to each 6354 motor.
Temperature readings show that the vesc remains cool, it was around 65F/18C outside.
Everything seems great so far!
Yep, I ride hard. Again, I’m only pushing 20 battery amps to each vesc, higher Amos may have different results but so far so good, and vescs are staying exceptionally cool as well.
I completed replacing the resistors on my 4.20 dual (not plus), but I’m not as skilled as some with micro-soldering. If I didn’t solder the resistors right, will the ESC still work? Are there some tests to ensure you soldered the pads well enough? After completion, my ESC works again, but at least on the bench I was still able to get it to shut down by giving it severe inputs.
Any advice would be much appreciated, I need a few beers after doing that job